The Ireland Data Protection Commission said in a report that since December it had 15 ongoing investigations of multinational tech companies. Ten of the investigations were about Facebook or its subsidiaries, Instagram and WhatsApp.

One of the investigations into Facebook is especially wide-ranging, examining whether the social network has met its obligations “to secure and safeguard the personal data of its users”. Twitter faces a similar probe, the report says.

The report shows how much Facebook’s handling of sensitive personal data is dominating legal and policy debates about privacy — and how much potential regulatory danger the social network faces in Europe, where privacy laws are stricter than the US.

The social notworking giant has its European headquarters in Dublin, meaning authorities in Ireland are the first line of defence for EU regulations.

However, the Irish commission has not announced the results of any investigations of Facebook, but potential penalties are high. Under a new privacy law that took effect in Europe in May 2018, companies that mishandle data can be fined up to 4 per cent of their annual global revenue.

The ten Irish investigations of Facebook cover a wide array of subjects. One is looking at how Facebook processes personal data for “behavioural analysis and targeted advertising”. Another is examining Instagram’s handling of personal information. A third is about the processing of information between WhatsApp and other Facebook subsidiaries.